Low back pain is considered one of the most widely experienced health problems in the U.S. and the world. This condition is second only to the common cold as the condition for which patients most frequently see a physician or suffer days lost from work. Estimated costs to those who are severely disabled from low back pain range from 30-70 billion dollars annually. Rates of spinal surgery in the U.S. have increased sharply over time, and 15-fold geographic variation in rates of these surgeries has been documented. In many cases the rates of surgery appear to be determined by where one lives and who one sees. Despite these trends, there is little evidence proving the effectiveness/efficacy of these therapies over non-operative management. This study will use the unique resource of the National Spine Network to conduct multicentered, randomized, controlled trials for the three most common diagnostic groups for which spine surgery is performed: lumbar intervertebral disc herniation (IDH), spinal stenosis (SpS) and spinal stenosis secondary to degenerative spondylolithesis (DS). The trials will compare the most commonly used standard surgical treatments to the most commonly used standard non-operative treatments. The study will be conducted at 16 sites throughout the United States. The primary endpoints of the study will be changes in general health-related quality of life as measured by the SF-36 health status questionnaire and spine-related disability as measured by the Oswestry Low Back Pain questionnaire. Secondary endpoints will include patient satisfaction with treatment, resource utilization for estimation of cost, and utility for current health for estimation of quality-adjusted life years (QALYs). The latter two endpoints will be used to complete a formal cost-effectiveness evaluation. Patients will be followed a minimum of 24 months with visits scheduled at 3, 6, 12, and 24 months. Data on all endpoints will be collected at each study visit. If possible, extended follow-up visits will be scheduled at 36 and 48 months. We anticipate that a total of 1450 subjects will be enrolled and randomly allocated. An additional observational cohort will be tracked to assess health and resource outcomes. Data from the RCT and observational cohorts will be integrated to formally estimate the cost-effectiveness of operative versus non-operative interventions for IDH, SpS, and DS. Based on this trial we will, for the first time, have scientific evidence as to the relative effectiveness/efficacy of surgical versus non-surgical treatment for these three common lumbar spine conditions.